Delivering on the promise: HPV vaccines and cervical cancer

Assessing the reduction of viral infectivity in HPV16/18-positive women after one, two, and three doses of Gardasil-9 (RIFT): Study protocol

Human Papillomavirus (HPV) prophylactic vaccination has proven effective in preventing new infections, but it does not treat existing HPV infections or associated diseases. Hence, there is still an important reservoir of HPV in adults, as vaccination programs are mainly focused on young women. The primary objective of this non-randomized, open-label trial is to evaluate if a 3-dose regimen of Gardasil-9 in HPV16/18-positive women could reduce the infective capacity of their body fluids. We aim to assess if vaccine-induced antibodies could neutralize virions present in the mucosa, thus preventing the release of infective particles and HPV transmission to sexual partners. As our main endpoint, the E1^E4-HaCaT model will be used to assess the infectivity rate of cervical, anal and oral samples, obtained from women before and after vaccination. HPV DNA positivity, virion production, seroconversion, and the presence of antibodies in the exudates, will be evaluated to attribute infectivity reduction to vaccination. Our study will recruit two different cohorts (RIFT-HPV1 and RIFT-HPV2) of non-vaccinated adult women. RIFT-HPV1 will include subjects with an HPV16/18 positive cervical test and no apparent cervical lesions or cervical lesions eligible for conservative treatment. RIFT-HPV2 will include subjects with an HPV16/18 positive anal test and no apparent anal lesions or anal lesions eligible for conservative treatment, as well as women with an HPV16/18 positive cervical test and HPV-associated vulvar lesions. Subjects complying with inclusion criteria for both cohorts will be recruited to the main cohort, RIFT-HPV1. Three doses of Gardasil-9 will be administered intramuscularly at visit 1 (0 months), visit 2 (2 months) and visit 3 (6 months). Even though prophylactic HPV vaccines would not eliminate a pre-existing infection, our results will determine if HPV vaccination could be considered as a new complementary strategy to prevent HPV-associated diseases by reducing viral spread. Trial registration: https://clinicaltrials.gov/ct2/show/NCT05334706.

2023 Korean sexually transmitted infections guidelines by the Korean Association of Urogenital Tract Infection and Inflammation: Human papillomavirus vaccination

The Korean Association of Urogenital Tract Infection and Inflammation (KAUTII) and the Korea Disease Control and Prevention Agency updated the guidelines for human papillomavirus (HPV) vaccine against sexually transmitted HPV infections in Korea to respond to changing epidemiologic trends, evolving scientific evidence, and advances in laboratory diagnostics and research. Main purpose and recommendation of vaccination against HPV are as follows: (1) the purpose of HPV vaccine is to reduce the risk of genital warts and HPV-related cancers including cervical and vulvar cancer, head and neck cancer, anal cancer, and penile cancer; (2) in Korea, bivalent (16, 18) vaccines, quadrivalent vaccines (6, 11, 16, 18), and 9-valent vaccines (6, 11, 16, 18, 31, 33, 45, 52, 58) are used depending on the type of HPV; (3) bivalent and quadrivalent vaccines are national immunizations targeting girls aged 11-12 years and low-income young females aged 18-26 years (age and range of inoculation: routinely administered at 11 or 12 years of age, 2 doses at 0 and 6 months for 12-14 years of age; for females aged 15-26 years, 3 doses depending on the type of vaccine; vaccination can be given to those aged up to 45 years through consultation with a clinician); (4) in the case of administering 2 doses, at least 5 months apart; in the case of administering 3 doses, it is recommended to keep 4 weeks between the 1st and 2nd doses, 12 weeks between the 2nd and 3rd doses, and 5 months between the 1st and 3rd doses; (5) immunocompromised patients such as those with HIV, malignant neoplasms, and autoimmune diseases, and those undergoing transplantation or immunosuppressive therapy should receive 3 doses. HPV vaccine is not recommended during pregnancy.

A Comprehensive Review of Treatment Approaches for Cutaneous and Genital Warts

Cutaneous and genital warts are common in both developed as well as developing countries. Human papillomavirus (HPV), which is a double-stranded DNA virus, is the causative agent of wart infection. Different types of HPV viruses are responsible for the different severity of diseases. Some types are associated with malignancy of the anal region and cervix. HPV is a common sexually transmitted disease in the United States. The incidence is most common in the younger age groups and the elderly population. Our main goal is to describe the different treatment modalities available for warts. Treatment modalities are divided into primary, secondary, and tertiary options. Topical medications, and physical excision of warts via cryotherapy, electrocautery, lasers, or photodynamic therapy are all common forms of treatment. Various clinical trials and randomized control trials have been seen as effective treatment against HPV infection. Higher remission rates are seen irrespective of different treatment options. Warts can be treated but the HPV virus cannot be completely removed. Older age, immunocompromised state, diabetes mellitus, and HIV are the predisposing factors for the disease. There is currently a large variety of medicines in use, all of which can differ significantly in terms of price, side-effect profiles, dosing regimens, length of therapy, and overall effectiveness. The best course of treatment has not yet been identified, and patients are often treated according to their unique needs.

Comparison of the Immune Responses to Different Formulations of BC02-Adjuvanted HPV Types 16 and 18 Bivalent Vaccines in Mice

To achieve maximum efficacy, vaccines, such as subunit, recombinant, and conjugate vaccines, necessitate the incorporation of immunostimulators/adjuvants. Adjuvants play a vital role in bolstering and extending the strength of the immune response while also influencing its type. As antigen and adjuvant formulations become more intricate, it becomes imperative to establish a well-characterized and robust formulation to ensure consistent and reproducible outcomes in preclinical and clinical studies. In the present study, an HPV bivalent vaccine was developed using a BC02 adjuvant in conjunction with HPV 16 and 18 L1 VLP antigens produced from an E. coli expression system. The study involved evaluating the adjuvant formulation and in vivo immunogenicity in mice. Remarkably, a medium-dose of BCG-CpG-DNA combined with a low-dose of aluminum hydroxide substantially enhanced the immunogenicity of HPV16 and 18 VLPs, resulting in improved cellular and humoral immune responses.

Development and validation of an HPV infection knowledge assessment scale among Aboriginal and Torres Strait Islander Peoples

Background

An increased incidence of Human Papillomavirus (HPV) infection and its related cancers has been observed in recent years. Correct knowledge about HPV infection can lead to a significant decrease in transmission and a subsequent increase in vaccine uptake. Awareness and behavioural perception towards HPV infections are critical for improving HPV vaccination rates among Aboriginal and/or Torres Strait Islander Peoples. However, to the best of our knowledge, there has been no instrument designed to measure knowledge about HPV infection that is culturally appropriate and validated among Aboriginal and/or Torres Strait Islander People.

Aim

To address this research gap, this paper aims to examine the psychometric properties of the HPV Knowledge Tool (HPV-KT) in an Indigenous population sample from South Australia.

Methodology

Data from 747 Indigenous Australian Adults who participated in the 12-month follow-up of the HPV and Oropharyngeal Carcinoma in Indigenous Australians Study was utilised for this study. The psychometric properties examined included1) dimensionality and item redundancy; (2) network loadings; (3) model fit; (4) criterion validity; and (5) reliability. The network model was estimated using the Graphical Least Absolute Shrinkage and Selector Operator (GLASSO). Evaluation of the HPV-KT (10 items) dimensionality and item redundancy was conducted within the framework of Exploratory Graph Analysis (EGA). Reliability was evaluated with the McDonald's Omega (ω) coefficient.

Results

After the exclusion of two items, the HPV-KT exhibited good psychometric properties for Aboriginal and/or Torres Strait Islander Peoples. The two dimensions of "General HPV Knowledge" and "Commonness of HPV" were identified. The dimension of "Commonness of HPV" displayed poor reliability, so a sum score for this subscale is not recommended (i.e. the items can still be used individually) The network model of the 7-item HPV-KT was fitted in the validation sample and model fit was adequate (x2 (7) = 17.17, p < 0.016; CFI = 0.980; TLI = 0.94; RMSEA = 0.063, 90% CI = 0.025-0.010). Furthermore, the reliability of the "General HPV Knowledge" subscale (ω = 0.76, 95% CI: 0.72-0.79), while the reliability of the "Commonness of HPV" subscale (ω = 0.58, 95% CI0.58-0.88) was poor.

Conclusion

The HPV-KT was adapted for an Aboriginal and/or Torres Strait Islander population and is readily available for future use in Australia. The addition of items assessing specifications of HPV infection, natural history and behaviour will improve the reliability and usability to assess the level of accurate knowledge about HPV infection. Future studies should investigate the possibility of developing new items for the dimension 'Commonness of HPV'.

Human Papilloma Virus: An Unraveled Enigma of Universal Burden of Malignancies

HPV, or Human Papilloma Virus, has been the primary causative agent of genital warts and cervical cancer worldwide. It is a sexually transmitted infection mainly affecting women of reproductive age group, also infecting men and high-risk group individuals globally, resulting in high mortality. In recent years, HPV has also been found to be the major culprit behind anogenital cancers in both gender and oropharyngeal and colorectal cancers. Few studies have reported the incidence of HPV in breast cancers as well. For a few decades, the burden of HPV-associated malignancies has been increasing at an alarming rate due to a lack of adequate awareness, famine vaccine coverage and hesitancy. The effectiveness of currently available vaccines has been limited to prophylactic efficacy and does not prevent malignancies associated with post-exposure persistent infection. This review focuses on the current burden of HPV-associated malignancies, their causes and strategies to combat the growing prevalence of the cancers. With the advent of new technologies associated with treatment pertaining to therapeutic interventions and employing effective vaccine coverage, the burden of this disease may be reduced in the population.

[14 years of HPV vaccination: what has been achieved?]

Professor Harald zur Hausen, „Vater der HPV(humane Papillomviren)-Impfung“, wurde in diesem Jahr 85 Jahre alt. Aus diesem Anlass wird in einem Rückblick auf die Einführung der HPV-Impfung vor 14 Jahren geschaut, und es werden die Widerstände aufgezeigt, welche die ersten Jahre dieser segensreichen Impfung begleiteten. Schon früh wurde 2007 die Impfung für die Mädchen in das Standardimpfprogramm der Ständigen Impfkommission am Robert Koch-Institut (STIKO) aufgenommen, erst 11 Jahre später kam es zur Empfehlung auch für Jungen. Die Impfquoten in beiden Gruppen sind mit ca. 50 % in Deutschland weiterhin im Vergleich zu anderen Ländern mit Schulimpfprogrammen zu niedrig. Dabei gibt es keine wissenschaftlichen Bedenken mehr gegenüber der HPV-Impfung, die sich in weltweiten Studien als sicher und wirksam erwiesen hat. Nicht nur die Verminderung der Krebsvorstufen, sondern auch von Zervixkarzinomen konnte neben der starken Reduktion von Fällen an Condylomata acuminata bei den Geimpften inzwischen in Real-Life-Studien gezeigt werden, weshalb die WHO (World Health Organization) als Impfziel die Eliminierung des Zervixkrebses durch Aufbau einer Bevölkerungsimmunität erklärt hat. Dazu sollten weitere Anstrengungen unternommen werden, die Impfquoten in Deutschland zu erhöhen, was auch in einem entsprechenden Appell der Gesundheitsministerkonferenz im Juni 2021 eingeflossen ist.

DeepVISP: Deep Learning for Virus Site Integration Prediction and Motif Discovery

Approximately 15% of human cancers are estimated to be attributed to viruses. Virus sequences can be integrated into the host genome, leading to genomic instability and carcinogenesis. Here, a new deep convolutional neural network (CNN) model is developed with attention architecture, namely DeepVISP, for accurately predicting oncogenic virus integration sites (VISs) in the human genome. Using the curated benchmark integration data of three viruses, hepatitis B virus (HBV), human herpesvirus (HPV), and Epstein-Barr virus (EBV), DeepVISP achieves high accuracy and robust performance for all three viruses through automatically learning informative features and essential genomic positions only from the DNA sequences. In comparison, DeepVISP outperforms conventional machine learning methods by 8.43-34.33% measured by area under curve (AUC) value enhancement in three viruses. Moreover, DeepVISP can decode cis-regulatory factors that are potentially involved in virus integration and tumorigenesis, such as HOXB7, IKZF1, and LHX6. These findings are supported by multiple lines of evidence in literature. The clustering analysis of the informative motifs reveales that the representative k-mers in clusters could help guide virus recognition of the host genes. A user-friendly web server is developed for predicting putative oncogenic VISs in the human genome using DeepVISP.

HPV vaccination: Are we overlooking additional opportunities to control HPV infection and transmission?

Human papillomavirus virus-like particles (HPV VLPs) have distinctive immunogenic properties that generate a durable antibody response, producing high-quality neutralizing antibodies. By vaccination, i.e., intramuscular injection of these HPV VLPs, the viral survival strategy of avoiding exposure to the systemic immune system is completely overruled, and large amounts of vaccine-induced systemic antibodies are generated. These systemic circulating antibodies are easily transuded to the genital mucosa and are detectable in female genital secretions. It is well accepted that these antibodies interact with the virions presented by an infected partner and inhibit infection. However, much less attention has been paid to the role of anti-HPV vaccine-induced antibodies in an HPV-infected individual where infectious virions are encountered by neutralizing antibodies in mucosal secretions. There is a clear need to further investigate and document this role. Indeed, if HPV vaccination of HPV-infected women has an effect on HPV transmission, auto-inoculation, and relapse after treatment, this may influence how we model, assess, and implement HPV vaccination programmes.

HPV-FASTER: Combined strategies of HPV vaccination and HPV screening towards a one visit for cervical cancer preventive campaigns

[Not available]

Should female sex workers be offered HPV vaccination?

Prophylactic vaccines are efficacious in preventing Human Papillomavirus (HPV) infection and subsequent cervical intraepithelial neoplasia (CIN), cervical cancer, other anogenital cancers, and anogenital warts. Female sex workers (SW) are at increased risk of acquiring sexually transmitted infections, including HPV. There are several reasons to offer HPV vaccination to SW: they are at high risk for HPV and often unvaccinated, and the immunogenicity of the vaccine is also excellent in previously HPV exposed women. Furthermore, women with disease caused by HPV may still benefit from vaccination. The efficacy of vaccinating mid-adult women (26-44 years old) against persistent HPV infection and CIN2+ is good. Although an SW may have been infected or exposed to HPV, she may not have been exposed to all vaccine-included hrHPV types. Vaccination induces mucosal immunity via the production of neutralizing antibodies on the surface of the female genital tract, thus preventing potential transmission to clients. Nevertheless, some considerations argue against offering vaccination to SWs. Current vaccines are only prophylactic and as such, do not affect current HPV infections. Women who have previously cleared HPV infections, may do so again and thus not need vaccination. Fewer SW might be naïve to HPV-types than currently thought. HPV vaccination has probably no effect on latent infections. Vaccinating sometime after sexual debut could be too late, as infections have already occurred. Taken together, some data suggest that vaccination of SW may offer health benefits, also for the community, but sufficient evidence is lacking. In certain cases, HPV vaccination of SW may be recommended. Evidence-based, public health decisions concerning vaccination of SW are challenging and could be facilitated with more research in this high-risk group.

Silencing of FTS increases radiosensitivity by blocking radiation-induced Notch1 activation and spheroid formation in cervical cancer cells

Increasing evidence(s) suggests that cancer stem cells (CSC) in tumours contribute to radio-resistance and recurrence. Notch plays an important role in the maintenance of CSC in many cancers including cervical cancer. Previously, we have reported the role of Fused Toes Homolog (FTS) in conferring radioresistance in cervical cancer cells in vitro and human subjects. The present study investigated the regulatory role of FTS in Notch signaling and maintenance of CSC upon irradiation of cervical cancer cells. The expression of Notch1, 2, 3, cleaved Notch1 and its downstream target Hes1, and spheroid formation was increased by irradiation. Silencing of FTS prevented the radiation-induced increase in the expression of Notch signaling molecules and spheroid formation. Immunoprecipitation showed FTS binds Notch1 and Hes1. Also in silico structural analysis identified putative residues responsible for the binding between FTS and Notch1. Spheroid formation and the expression of CSC markers, Nanog, Oct4A and Sox2 were greatly reduced by combining silencing of FTS and radiation. Taken together, these results suggest that FTS is involved in the regulation of irradiation-induced Notch signaling and CSC activation and can be used as a target to increase radiosensitivity in cervical cancer.

Therapeutic vaccines for high-risk HPV-associated diseases

Cancer is the second leading cause of death worldwide, and it is estimated that Human papillomavirus (HPV) related cancers account for 5% of all human cancers. Current HPV vaccines are extremely effective at preventing infection and neoplastic disease; however, they are prophylactic and do not clear established infections. Therapeutic vaccines which trigger cell-mediated immune responses for the treatment of established infections and malignancies are therefore required. The E6 and E7 early genes are ideal targets for vaccine therapy due to their role in disruption of the cell cycle and their constitutive expression in premalignant and malignant tissues. Several strategies have been investigated for the development of therapeutic vaccines, including live-vector, nucleic acid, peptide, protein-based and cell-based vaccines as well as combinatorial approaches, with several vaccine candidates progressing to clinical trials. With the current understanding of the HPV life cycle, molecular mechanisms of infection, carcinogenesis, tumour biology, the tumour microenvironment and immune response mechanisms, an approved HPV therapeutic vaccine seems to be a goal not far from being achieved. In this article, the status of therapeutic HPV vaccines in clinical trials are reviewed, and the potential for plant-based vaccine production platforms described.

Computational identification, characterization and validation of potential antigenic peptide vaccines from hrHPVs E6 proteins using immunoinformatics and computational systems biology approaches

High-risk human papillomaviruses (hrHPVs) are the most prevalent viruses in human diseases including cervical cancers. Expression of E6 protein has already been reported in cervical cancer cases, excluding normal tissues. Continuous expression of E6 protein is making it ideal to develop therapeutic vaccines against hrHPVs infection and cervical cancer. Therefore, we carried out a meta-analysis of multiple hrHPVs to predict the most potential prophylactic peptide vaccines. In this study, immunoinformatics approach was employed to predict antigenic epitopes of hrHPVs E6 proteins restricted to 12 Human HLAs to aid the development of peptide vaccines against hrHPVs. Conformational B-cell and CTL epitopes were predicted for hrHPVs E6 proteins using ElliPro and NetCTL. The potential of the predicted peptides were tested and validated by using systems biology approach considering experimental concentration. We also investigated the binding interactions of the antigenic CTL epitopes by using docking. The stability of the resulting peptide-MHC I complexes was further studied by molecular dynamics simulations. The simulation results highlighted the regions from 46–62 and 65–76 that could be the first choice for the development of prophylactic peptide vaccines against hrHPVs. To overcome the worldwide distribution, the predicted epitopes restricted to different HLAs could cover most of the vaccination and would help to explore the possibility of these epitopes for adaptive immunotherapy against HPVs infections.

Cancer Vaccines: Past, Present, and Future

Cancer is a common and potentially deadly disease. Some of the cancers may be difficult to treat by conventional means such as surgery, radiation, and chemotherapy, but may be controlled by the stimulation of the immune response of the body with the help of cancer vaccines. The use of vaccines for preventing infections by oncogenic viruses such as hepatitis B virus and human papilloma virus has been extremely successful in reducing the incidence of cancers resulting from these infections. The use of vaccines for treating cancers that are not due to viral infections and that are already established is currently the object of numerous clinical trials. Several types of cancer vaccines are being tried. These include antigen vaccines, tumor cell vaccines, dendritic vaccines, deoxyribonucleic acid vaccines, and viral vector vaccines. The development of these therapeutic vaccines is proving difficult with only 1 recent success. However, there is significant enthusiasm and optimism regarding the development of effective therapeutic vaccines stemming from the fact that our understanding regarding the cancer immunology is considerably enhanced in recent years. This expanded knowledge regarding the mechanisms that cancers use to escape the immune system is likely to open new avenues in modulating the immune response to cancer, thus enhancing the effectiveness of therapeutic cancer vaccines.

Co-infection of Epstein-Barr virus and human papillomavirus in human tumorigenesis

Viral infections contribute to approximately 12% of cancers worldwide, with the vast majority occurring in developing countries and areas. Two DNA viruses, Epstein-Barr virus (EBV) and human papillomavirus (HPV), are associated with 38% of all virus-associated cancers. The probability of one patient infected with these two distinct types of viruses is increasing. Here, we summarize the co-infection of EBV and HPV in human malignancies and address the possible mechanisms for the co-infection of EBV and HPV during tumorigenesis.

In silico mechanistic analysis of IRF3 inactivation and high-risk HPV E6 species-dependent drug response

The high-risk human papillomavirus E6 (hrHPV E6) protein has been widely studied due to its implication in cervical cancer. In response to viral threat, activated kinases phosphorylate the IRF3 autoinhibitory domain, inducing type1 interferon production. HPV circumvents the antiviral response through the possible E6 interaction with IRF3 and abrogates p53's apoptotic activity by recruiting E6-associated protein. However, the molecular mechanism of IRF3 inactivation by hrHPV E6 has not yet been delineated. Therefore, we explored this mechanism through in silico examination of protein-protein and protein-ligand docking, binding energy differences, and computational alanine mutagenesis. Our results suggested that the LxxLL motifs of IRF3 binds within the hydrophobic pocket of E6, precluding Ser-patch phosphorylation, necessary for IRF3 activation and interferon induction. This model was further supported by molecular dynamics simulation. Furthermore, protein-ligand docking and drug resistance modeling revealed that the polar patches in the pocket of E6, which are crucial for complex stability and ligand binding, are inconsistent among hrHPV species. Such variabilities pose a risk of treatment failure owing to point mutations that might render drugs ineffective, and allude to multi-drug therapy. Overall, this study reveals a novel perspective of innate immune suppression in HPV infections and suggests a plausible therapeutic intervention.

Vaccine-elicited CD8+ T cells cure mesothelioma by overcoming tumor-induced immunosuppressive environment

Eradicating malignant tumors by vaccine-elicited host immunity remains a major medical challenge. To date, correlates of immune protection remain unknown for malignant mesothelioma. In this study, we demonstrated that antigen-specific CD8(+) T-cell immune response correlates with the elimination of malignant mesothelioma by a model PD-1-based DNA vaccine. Unlike the nonprotective tumor antigen WT1-based DNA vaccines, the model vaccine showed complete and long-lasting protection against lethal mesothelioma challenge in immunocompetent BALB/c mice. Furthermore, it remained highly immunogenic in tumor-bearing animals and led to therapeutic cure of preexisting mesothelioma. T-cell depletion and adoptive transfer experiments revealed that vaccine-elicited CD8(+) T cells conferred to the protective efficacy in a dose-dependent way. Also, these CD8(+) T cells functioned by releasing inflammatory IFNγ and TNFα in the vicinity of target cells as well as by initiating TRAIL-directed tumor cell apoptosis. Importantly, repeated DNA vaccinations, a major advantage over live-vectored vaccines with issues of preexisting immunity, achieve an active functional state, not only preventing the rise of exhausted PD-1(+) and Tim-3(+) CD8(+) T cells but also suppressing tumor-induced myeloid-derived suppressive cells and Treg cells, with the frequency of antigen-specific CD8(+) T cells inversely correlating with tumor mass. Our results provide new insights into quantitative and qualitative requirements of vaccine-elicited functional CD8(+) T cells in cancer prevention and immunotherapy.

Biological significance and therapeutic implication of resveratrol-inhibited Wnt, Notch and STAT3 signaling in cervical cancer cells

Cervical cancers/CCs are one of the commonest malignancies and the second leading cause of cancer-related death in women. Resveratrol inhibits CC cell growth but its molecular target(s) remains unclear. Since the signaling pathways mediated by STAT3, Notch1 and Wnt2 play beneficial roles in CC formation and progression, the effects of resveratrol on them in cervical adenocarcinoma (HeLa) and squamous cell carcinoma (SiHa) cells were analyzed. The biological significances of the above signaling for HeLa and SiHa cells were evaluated by treating the cells with STAT3, Wnt or Notch selective inhibitors. The frequencies of STAT3, Notch and Wnt activations in 68 cases of CC specimens and 38 non-cancerous cervical epithelia were examined by tissue microarray-based immunohistochemical staining. The results revealed that HeLa and SiHa cells treated by 100μM resveratrol showed extensive apoptosis, accompanied with suppression of STAT3, Notch and Wnt activations. Growth inhibition and apoptosis were found in HeLa and SiHa populations treated by AG490, a STAT3/JAK3 inhibitor but not the ones treated by Notch inhibitor L-685,458 or by Wnt inhibitor XAV-939. Immunohistochemical staining performed on the tissue microarrays showed that the frequencies of Notch1, Notch2, Hes1, Wnt2, Wnt5a and p-STAT3 detection as well as β-catenin nuclear translocation in CC samples were significantly higher than that of noncancerous group (p<0.01), while the expression rate of PIAS3 was remarkably low in cancer samples (p<0.01). Our results thus demonstrate that STAT3, Wnt and Notch signaling are frequently co-activated in human CC cells and specimens and resveratrol can concurrently inhibit those signaling activations and meanwhile lead cervical squamous cell carcinoma and adenocarcinoma cells to growth arrest and apoptosis. STAT3 signaling is more critical for CC cells and is the major target of resveratrol because selective inhibition of STAT3 rather than Wnt or Notch activation commits SiHa and HeLa cells to apoptosis.

Potential anti-HPV and related cancer agents from marine resources: an overview

Recently, the studies on the prevention and treatment of human papillomavirus (HPV) which is closely related to the cervical cancer and other genital diseases are attracting more and more attention all over the world. Marine-derived polysaccharides and other bioactive compounds have been shown to possess a variety of anti-HPV and related cancer activities. This paper will review the recent progress in research on the potential anti-HPV and related cancer agents from marine resources. In particular, it will provide an update on the anti-HPV actions of heparinoid polysaccharides and bioactive compounds present in marine organisms, as well as the therapeutic vaccines relating to marine organisms. In addition, the possible mechanisms of anti-HPV actions of marine bioactive compounds and their potential for therapeutic application will also be summarized in detail.

Human papillomavirus vaccination and Pap testing profile in Manitoba, Canada

BACKGROUND

Females who receive the human papillomavirus (HPV) vaccine may believe they are protected from developing cervical cancer and no longer require screening. Concern has also been expressed that vaccinated females are those that would be screened regularly. This study assesses the Pap testing behavior of vaccinated and non-vaccinated females.

METHODS

For this population-based retrospective cohort study, vaccination and screening registries were linked for 3540 vaccinated females aged 15 years and over and 9592 matched non-vaccinated females. Conditional logistic regression, the Kaplan-Meier method and Cox regression were used to examine the association between vaccination and Pap testing.

RESULTS

Vaccinated females were more likely to have had a Pap test within the year prior to the index date than non-vaccinated females (15-19 years old: OR=1.38, 95% CI 1.20-1.59; 20+ years old: OR=2.34, 95% CI 1.98-2.76). In the three-year period after the index date, vaccinated females had a significantly higher cumulative probability of having a Pap test (83.3%) than non-vaccinated females (66.1%). Females who had a Pap test within three years prior to the index date were more likely to have a Pap test after the index date (vaccinated: HR=5.03, 95% CI 4.65-5.45; non-vaccinated HR=3.97, 95% CI 3.70-4.24). Being vaccinated had a significant effect on Pap testing (15-19 years old: HR=1.54, 95% CI 1.39-1.69; 20+ years old: HR=1.87, 95% CI 1.52-2.31). 80.1% of vaccinated females who had a Pap test prior to the index date also had one subsequent to it, compared to 70.1% for non-vaccinated females. 41.1% of females had not been vaccinated nor had a Pap test.

CONCLUSION

The majority of vaccinated females continue to participate in screening, and do so at a higher rate than non-vaccinated females. Renewed efforts need to be made to include the large proportion of non-vaccinated, non-screened females in vaccination and/or screening.

Mothers' human papilloma virus knowledge and willingness to vaccinate their adolescent daughters in Lagos, Nigeria

INTRODUCTION

Human papillomavirus (HPV) is one of the most common sexually transmitted infections in sexually active adolescents and young women and has been implicated as a cause of the majority of cases of cervical cancer, which is the second most common cancer in women in Nigeria. HPV is preventable with the use of HPV vaccines.

OBJECTIVES

The objective of this study was to assess mothers' HPV knowledge and their willingness to vaccinate their adolescent daughters in Lagos, Nigeria.

MATERIALS AND METHODS

This study was a community-based, descriptive cross-sectional study carried out in July, 2012 in Shomolu Local Government Area (LGA) of Lagos State, Nigeria. Multistage sampling method was employed to select the 290 respondents who participated in the study. Structured, pretested, interviewer-administered questionnaires were used for data collection. Data was analyzed with Epi Info™ version 7.

RESULTS

The study revealed low awareness of HPV (27.9%) and HPV vaccines (19.7%) among the mothers that participated. There was a high awareness for cervical cancer but little knowledge of its link to HPV. Awareness and utilization of HPV vaccines increased with increasing educational level (P < 0.05). There was a high willingness and intention among the mothers to vaccinate their girls (88.9%) and to recommend the vaccine to others (91.0%). Accessibility and affordability of the HPV vaccines were found to be possible barriers to future utilization of the vaccines.

CONCLUSION

Despite low knowledge about HPV and HPV vaccines, mothers were willing to vaccinate their daughters. We recommend improving mothers' knowledge by education and the possible inclusion of the vaccine in the national immunization schedule to eliminate the financial barrier.

Recent progress in the application of nanotechnology for prevention and treatment of human papillomavirus infection

Human papillomavirus (HPV) causes benign and malignant infections of the anogenital tract. Cervical cancer, caused by high-risk HPV types 16, 18, 31, 33, 35, 45, 56 and 58, is the second most common cancer in women and the fifth most common cancer overall. Prevention and treatment of HPV infection may be revolutionized using nanotechnology tools such as vaccines based on virus-like particles and nanoscale drug-delivery systems. Advances in both virus-like particle design and noninvasive delivery of antiviral protein drugs, such as IFNalpha, may provide new opportunities to take on the challenge of global elimination of HPV infections. Biphasic vesicle cream formulation, representing a new class of dermal delivery system for protein drugs, is an alternative to injectable dosage form to deliver IFNalpha for the treatment of HPV infections, showing efficacy in low-grade squamous epithelical lesions of the cervix.

Next Generation Cancer Protection: The Bivalent HPV Vaccine for Females

Nearly a half a million women throughout the world develop cervical cancer every year Parkin and Bray ("Chapter 2. The burden of HPVrelated cancers," Vaccine, vol. 24, no. 3, pp. S11-S25, 2006); 80% of these women are in countries without a quality-assured cytology screening program. It is in this setting that Cervarix could reduce the incidence of cervical cancer to about 9.5/100,000 women. New evidence indicates that this might be able to be accomplished with a single dose of Cervarix, a great advantage to public health implementation programs Kreimer et al. ("Proof-of-principle evaluation of the efficacy of fewer than three doses of a bivalent HPV16/18 vaccine, The Journal of the National Cancer Institute, vol. 103, no. 19, pp. 1444-1451, 2011). In countries with screening programs, adenocarcinoma is the most difficult to detect and treat with later-stage presentation and higher mortality Smith et al. ("The rising incidence of adenocarcinoma relative to squamous cell carcinoma of the uterine cervix in the United States-a 24-year population-based study," Gynecologic Oncology, vol. 78, no. 2, pp. 97-105, 2000) and Gunnell et al. ("A longitudinal Swedish study on screening for squamous cell carcinoma and adenocarcinoma: evidence of effectiveness and overtreatment," Cancer Epidemiology Biomarkers and Prevention, vol. 16, no. 12, pp. 2641-2648, 2007). With additional cross-protection to HPV 31, 33, and 45 and protection against HPV 16 and 18 lasting at least 9.4 years, Cervarix may reduce adenocarcinomas in screened populations by more than 90%. This paper will detail the evidence about the efficacy, immunogenicity, and safety of Cervarix in the studied populations contrasting public health goals with individual health options.

Expression of codon optimized major capsid protein (L1) of human papillomavirus type 16 and 18 in Pichia pastoris; purification and characterization of the virus-like particles

The major capsid protein (L1) of human papillomaviruses (HPV) expressed in heterologous systems assembles into virus-like particles (VLPs). We report cloning and expression of codon optimized HPV L1 genes of the two high-risk HPV types 16 and 18 in methylotropic yeast, Pichia pastoris. The VLPs produced in P. pastoris were subjected to three step purification method involving density gradient centrifugations and size exclusion chromatography. The enriched VLPs were characterized using conformation-specific monoclonal antibodies in ELISA and by transmission electron microscopy. Mice immunized with a bivalent HPV16 and HPV18 VLPs developed high serum antibody titers to both HPV types that persisted for 190 days post vaccination. Serum of mice immunized with the HPV-VLP preparations could neutralize homologous pseudoviruses in an in vitro assays. Our results demonstrate that the L1 proteins expressed in P. pastoris fold properly as evidenced by assembly into VLPs and induction of type-specific neutralizing antibody response in mice. This work constitutes a step towards developing an alternate production platform for generating an affordable HPV vaccine to meet the needs of developing countries.

Potential role of marine algae on female health, beauty, and longevity

Marine environment has been known as a rich source of chemical structures with numerous health benefit effects. Among marine organisms, marine algae have been identified as an underexploited plant resource although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities of marine algae in promoting female health, beauty, and longevity. Hence, marine algae have a great potential to be used as a part of pharmaceuticals, nutraceuticals, and functional foods. This contribution presents an overview of marine algal potential effect in promoting female health, beauty, and longevity.

Monitoring of human papillomavirus vaccination

Persistent infection with oncogenic human papillomavirus (HPV) is a necessary causal factor in the development of cervical cancer. Moreover, HPV, predominately type 16 and to a lesser degree type 18, is linked causally to varying proportions of other anogenital cancers (vulva, vagina, penis, anus) as well as cancers elsewhere in the body (oropharynx, larynx, conjunctiva). HPV types 6 and 11 cause most of genital warts and recurrent respiratory papillomatosis. Effective prophylactic vaccines have been developed. In this review, we address briefly the immunological aspects of HPV infection and the results of HPV vaccination trials. Internationally standardized monitoring and evaluation of prophylactic HPV vaccination programmes will be essential for arriving at the most cost-effective strategies for cancer control.

Vaccination with a human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine in Korean girls aged 10-14 years

The human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine has been demonstrated to be highly efficacious and immunogenic with a favorable safety profile. This study assessed the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Korean girls aged 10-14 yr. This multi-center, observer-blind trial randomly assigned 321 healthy girls to receive three doses (0, 1, 6-month schedule) of HPV-16/18 AS04-adjuvanted vaccine or hepatitis A vaccine. Immunogenicity against vaccine antigens was assessed one month post-Dose 3. Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. In the according-to-protocol analysis, all initially seronegative subjects vaccinated with the HPV-16/18 AS04-adjuvanted vaccine had seroconverted at Month 7, with a peak geometric mean titer (GMT) that was 600-fold higher than the natural infection titer of 29.8 EU/mL for HPV-16 and a peak GMT that was 400-fold higher than the natural infection titer of 22.6 EU/mL for HPV-18. The vaccine was well tolerated with no increase in reactogenicity with subsequent doses and no reports of vaccine-related SAEs. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine is shown to be highly immunogenic and generally well-tolerated in Korean girls aged 10-14 yr.

Listeria monocytogenes delivery of HPV-16 major capsid protein L1 induces systemic and mucosal cell-mediated CD4+ and CD8+ T-cell responses after oral immunization

Neutralizing antibodies are thought to be required at mucosal surfaces to prevent human papillomavirus (HPV) transmission. However, the potential for cell-mediated immunity in mediating protection against HPV infection has not been well explored. We generated recombinant Listeria monocytogenes (Lm) constructs that secrete listeriolysin O (LLO) fused with overlapping N-terminal (LLO-L1(1-258)) or C-terminal (LLO-L1(238-474)) fragments of HPV type 16 major capsid protein L1 (HPV-16-L1). Oral immunization of mice with either construct induced IFN-gamma-producing CD8+ and CD4+ T cells in the spleen and in the Peyer's patches with the C-terminal construct. Oral immunization with both constructs resulted in diminished viral titers in the cervix and uterus of mice after intravaginal challenge with vaccinia virus expressing HPV-16-L1.

Recombinant measles virus-HPV vaccine candidates for prevention of cervical carcinoma

Cervical cancer is mainly associated with HPV genotype 16 infection. Recombinant measles virus (rMV) expressing HPV genotype 16 L1 capsid protein was generated by construction of an antigenomic plasmid, followed by rescue using the human "helper" cell line 293-3-46. In cell cultures the recombinant MV-L1 virus replicated practically as efficiently as the standard attenuated MV established as commercial vaccine, devoid of the transgene. The high genetic stability of MVb2-L1 was confirmed by 10 serial viral transfers in cell culture. In transgenic mice expressing the MV receptor CD46 the recombinant induced strong humoral immune responses against both MV and HPV; the antibodies against L1 exhibited mainly neutralizing capacity. Our data suggest that MV is a promising vehicle for development of inexpensive and efficient vaccines protecting from HPV infection.

Clinical follow-up of women infected with human papillomavirus-16, either alone or with other human papillomavirus types: identification of different risk groups

OBJECTIVES

Evaluation of the clinical impact of multiple infections of the cervix by human papillomavirus, including human papillomavirus-16, compared with single human papillomavirus-16 infection.

STUDY DESIGN

One hundred sixty-nine women were classified in 3 categories depending on their human papillomavirus profile: human papillomavirus-16 only, human papillomavirus-16 and low-risk type(s), and human papillomavirus-16 and other high-risk type(s). Cervical brush samples were analyzed for human papillomavirus DNA by polymerase chain reaction and reverse line blot hybridization. All women were evaluated with colposcopy during 24 months or more. Management was according to the Bethesda recommendations.

RESULTS

Women infected with human papillomavirus-16 and other high-risk human papillomavirus type(s) presented more progression or no change in the grade of dysplasia, compared with women of the other groups (relative risk [RR], 1.39; 95% confidence interval [CI], 1.07-1.82; P = .02 at 6 months; RR, 2.10; 95% CI, 1.46-3.02; P < .001 at 12 months; RR, 1.82; 95% CI, 1.21-2.72; P = .004 at 24 months).

CONCLUSION

Coinfection of women with human papillomavirus-16 and other high-risk human papillomavirus type(s) increases the risk of unfavorable evolution.

Establishment of human papillomavirus infection requires cell cycle progression

Human papillomaviruses (HPVs) are DNA viruses associated with major human cancers. As such there is a strong interest in developing new means, such as vaccines and microbicides, to prevent HPV infections. Developing the latter requires a better understanding of the infectious life cycle of HPVs. The HPV infectious life cycle is closely linked to the differentiation state of the stratified epithelium it infects, with progeny virus only made in the terminally differentiating suprabasal compartment. It has long been recognized that HPV must first establish its infection within the basal layer of stratified epithelium, but why this is the case has not been understood. In part this restriction might reflect specificity of expression of entry receptors. However, this hypothesis could not fully explain the differentiation restriction of HPV infection, since many cell types can be infected with HPVs in monolayer cell culture. Here, we used chemical biology approaches to reveal that cell cycle progression through mitosis is critical for HPV infection. Using infectious HPV16 particles containing the intact viral genome, G1-synchronized human keratinocytes as hosts, and early viral gene expression as a readout for infection, we learned that the recipient cell must enter M phase (mitosis) for HPV infection to take place. Late M phase inhibitors had no effect on infection, whereas G1, S, G2, and early M phase cell cycle inhibitors efficiently prevented infection. We conclude that host cells need to pass through early prophase for successful onset of transcription of the HPV encapsidated genes. These findings provide one reason why HPVs initially establish infections in the basal compartment of stratified epithelia. Only this compartment of the epithelium contains cells progressing through the cell cycle, and therefore it is only in these cells that HPVs can establish their infection. By defining a major condition for cell susceptibility to HPV infection, these results also have potentially important implications for HPV control.

Human papillomaviruses (HPV), which comprise more than 100 genotypes, are the most prevalent sexually transmitted infection and are associated with multiple human cancers including all cervical cancers, many other anogenital cancers, and 25% of head and neck cancers. The HPV life cycle is closely linked to epithelial differentiation of skin keratinocytes, with initial infection occurring only in the undifferentiated proliferating basal compartment of the epithelium and progeny virus production only in the terminally differentiated suprabasal compartment. So far, little is known about how host cells restrict the HPV life cycle to specific stages of skin cell development. Here, by identifying small molecule inhibitors of HPV infection, we discovered that cell cycle progression through mitosis is critical for the establishment of HPV infection. In addition, our further chemical genetic dissection of this process showed that early steps of mitosis are required for HPV infection and early gene expression. Our findings provide one reason why HPV only infects undifferentiated proliferating cells and provide new leads for the development of preventive and therapeutic strategies against HPV infection.

Preventing cervical cancer : overviews of the National Breast and Cervical Cancer Early Detection Program and 2 US immunization programs

Three federal programs with the potential to reduce cervical cancer incidence, morbidity, and mortality, especially among underserved populations, are administered by the Centers for Disease Control and Prevention (CDC): the National Breast and Cervical Cancer Early Detection Program (NBCCEDP), the Vaccines for Children (VFC) Program, and the Section 317 immunization grant program. The NBCCEDP provides breast and cervical cancer screening and diagnostic services to uninsured and underinsured women. The VFC program and the Section 317 immunization grant program provide vaccines, including human papillomavirus (HPV) vaccine, to targeted populations at no cost for these vaccines. This article describes the programs, their histories, populations served, services offered, and roles in preventing cervical cancer through HPV vaccination and cervical cancer screening. Potential long-term reduction in healthcare costs resulting from HPV vaccination is also discussed. As an example of an initiative to vaccinate uninsured women aged 19-26 years through a cancer services program, a state-based effort that was recently launched in New York, is highlighted.

Cervical and vulvar cancer risk in relation to the joint effects of cigarette smoking and genetic variation in interleukin 2

Cigarette smoking is an established cofactor to human papillomavirus (HPV) in the development of cervical and vulvar squamous cell carcinoma (SCC), and may influence risk through an immunosuppressive pathway. Genetic variation in interleukin 2 (IL2), associated in some studies with the inhibition of HPV-targeted immunity, may modify the effect of smoking on the risk of HPV-related anogenital cancers. We conducted a population-based case-only study to measure the departure from a multiplicative joint effect of cigarette smoking and IL2 variation on cervical and vulvar SCC. Genotyping of the four IL2 tagSNPs (rs2069762, rs2069763, rs2069777, and rs2069778) was done in 399 cervical and 486 vulvar SCC cases who had been interviewed regarding their smoking history. Compared with cases carrying the rs2069762 TT genotype, we observed significant departures from multiplicativity for smoking and carriership of the TG or GG genotypes in vulvar SCC risk [interaction odds ratio (IOR), 1.67; 95% confidence interval (CI), 1.16-2.41]. Carriership of one of three diplotypes, together with cigarette smoking, was associated with either a supramultiplicative (TGCT/GGCC; IOR, 2.09; 95% CI, 0.98-4.46) or submultiplicative (TTCC/TGTC; IOR, 0.37; 95% CI, 0.16-0.85 or TGCT/TGCC; IOR, 0.37; 95% CI, 0.15-0.87) joint effect in vulvar cancer risk. For cervical SCC, departure from multiplicativity was observed for smokers homozygous for the rs2069763 variant allele (TT versus GG or GT genotypes; IOR, 1.87; 95% CI, 1.00-3.48), and for carriership of the TTCC/TTCC diplotype (IOR, 2.08; 95% CI, 1.01-4.30). These results suggest that cervical and vulvar SCC risk among cigarette smokers is modified by genetic variation in IL2.

Immunogenicity and tolerability of an HPV-16/18 AS04-adjuvanted prophylactic cervical cancer vaccine in women aged 15-55 years

The immunogenicity and safety of an HPV-16/18 AS04-adjuvanted vaccine were assessed in women aged 26-55 years and compared with women aged 15-25 years in a Phase III, non-randomised, open-label, age-stratified study. Overall the vaccine was well tolerated and 100% seropositivity was achieved 1 month after the third dose in all age groups. There was a high correlation between HPV-16 and HPV-18 antibody levels (IgG) in cervicovaginal secretions and sera, regardless of age. The HPV-16/18 AS04-adjuvanted vaccine induces a robust and persistent immune response in women >26 years of age and generates antibodies that transudate through the cervix epithelium.

Women's knowledge, attitudes, and intentions concerning Human Papillomavirus vaccination: findings of a waiting room survey of obstetrics-gynaecology outpatients

OBJECTIVE

To assess women's knowledge, attitudes, and behaviours related to Human Papillomavirus (HPV) and HPV vaccination.

METHODS

A self-administered questionnaire was completed by 98 women (90.7% response rate) attending a hospital-based obstetrics and gynaecology outpatient clinic in a mid-size Ontario city.

RESULTS

Women had a moderate level of knowledge of general HPV-related issues, but lacked information about the ability of barrier contraception to prevent HPV and about characteristics of HPV vaccination. Women were strongly supportive of HPV vaccination for both male and female teenagers, but reported low levels of intention to receive vaccination themselves. Physician recommendation was the most influential factor in women intention to be vaccinated, and younger women were more likely to say they intended to be vaccinated. HPV-related knowledge, level of education, and number of previous sexual partners were unrelated to women's intentions to receive HPV vaccination.

CONCLUSION

Findings indicate that women's knowledge about HPV vaccination is inconsistent, that women are supportive of vaccinating both male and female teenagers, and that physician recommendation and younger age are associated with women's interest in receiving the vaccine.

Prophylactic HPV vaccines: new interventions for cancer control

Human Papillomavirus (HPV) infection causes cervical cancer, a significant portion of anal, vulvar, vaginal, and oropharyngeal cancers, genital warts, and recurrent respiratory papillomatosis (RRP). HPV 16 and 18 cause 70-90% of HPV-related cancers whereas HPV 6 and 11 cause 90% of RRP and genital wart cases. Together these four types cause 30-50% of all cervical intraepithelial neoplasia such as those detected by Papinicalou screening. In June 2006, a quadrivalent HPV (6, 11, 16, 18) vaccine was licensed in the United States, and subsequently in the European Union (September 2006), both following expedited review. We describe the primary objectives of the quadrivalent HPV vaccine clinical trial program including studies in females aged 9-45 and males aged 9-26. Planned long-term efficacy and safety evaluations, as well as programs to evaluate vaccine impact on oropharyngeal cancer are also described.

Indications and efficacy of the human papillomavirus vaccine

In the United States, there are 11,150 cases and 3670 deaths projected due to invasive cervical cancer for 2007. Approximately 500,000 new cases and 274,000 deaths will occur in women throughout the world. Human papillomavirus (HPV) has been designated by the World Health Organization (WHO) as a "necessary cause" of cervical cancer. There are 6.2 million new cases of HPV diagnosed each year. In addition to cervical cancer, the virus has also been implicated in vaginal, vulvar, penile, anal, and head and neck cancers. Current methods for prevention of cervical cancer include Pap smears, HPV testing, ablative procedures, cervical conization, and hysterectomy. These are costly as well as invasive. The HPV vaccine is the most recent breakthrough for the prevention of cervical cancer. The quadrivalent HPV vaccine (Gardasil) covers types 6, 11, 16, & 18. The bivalent vaccine (Cervarix) covers types 16 & 18, and is expected to come out in the early part of 2007. Approximately 70% of cervical cancer is caused by HPV types 16 & 18. HPV types 6 &11 are responsible for 90% of anogenital warts. Females of ages 11-12 and those prior to their sexual debut should be vaccinated, with all females in the age range of 9-26 also eligible. This vaccination strategy can prevent the above HPV infections, cervical dysplasia, and possibly cervical cancer.

Enhanced immunogenicity of HPV16E7 accompanied by Gp96 as an adjuvant in two vaccination strategies

Human papillomavirus, particularly type 16 (HPV16) is present in more than 99% of cervical cancers. E7 is the major oncogenic protein produced in cervical cancer-associated HPV16. An efficient vaccine against viral infection requires induction of strong humoral and cellular responses against viral proteins. Heat shock proteins (HSPs) like Gp96 have been described as potent tumor vaccines in animal models and are currently studied in human clinical trials. In this study, we investigated the utility of HPV16 E7 along with Gp96 as an adjuvant in C57BL/6 mice model. We compared the level of humoral and cellular immune responses by E7+Gp96 co-injection as DNA/DNA and prime-boost (DNA/protein) immunization strategies. In prime-boost immunization strategies, we first immunized C57BL/6 mice with the complete open-reading frame of E7 and Gp96 (pcDNA-E7 and pcDNA-Gp96) and then boosted with rE7, rNT-gp96 (N-terminal extension of Gp96) and rCT-gp96 (C-terminal extension of Gp96) mixed with Montanide 720 in different formulations. The humoral immune responses against rE7 and the different truncated forms of rGp96 suggested a mixed Th1/Th2 response with high intensity toward Th2. Assessment of lymphoproliferative and cytokine responses against rE7 and the different fragments of Gp96, showed that DNA vaccination including E7 and Gp96 induced Th1 response. We concluded that co-delivery of naked DNA E7+Gp96 plasmid was immunologically more effective than E7 alone. Our study demonstrated that co-delivery of E7+Gp96 as DNA/DNA and E7+CT-gp96 as DNA/protein could be an effective approach to induce E7-specific immune responses as a potential vaccine candidate for cervical cancer.

Oral immunization with different assembly forms of the HPV 16 major capsid protein L1 induces neutralizing antibodies and cytotoxic T-lymphocytes

Human papillomaviruses have been recognized as the causative agent of anogenital cancer. In 2006, a commercial vaccine based on virus-like particles composed of the L1 major capsid protein of the papillomaviruses has been available. This vaccine induces virus-neutralizing antibody responses upon parenteral injection. Here we investigated the oral immunogenicity of different assembly forms of HPV 16 L1, that is: T7-VLPs, T1 particles and capsomeres. Our results show that all three assembly forms induce humoral and cellular immune responses after oral vaccination of mice. The anti-L1 antibodies were conformation-specific and showed neutralizing activity in a pseudovirion-based assay. We also investigated if adjuvants have an influence on the oral immunogenicity of the different L1 forms. For saponins we observed a significant toxicity if applied orally. Co-administration of either CpG DNA or Escherichia coli heat-labile enterotoxin LT(R192G) had no apparent enhancing effect on the production of anti-L1 antibodies. More pronounced was the effect of CpG administration on the long-term immunity as we observed a significantly stronger recall response 244 days after the first vaccination. Compared to capsomeres, VLPs induced stronger humoral immune responses while the CTL responses were induced at comparable levels. Finally, we were also able to induce neutralizing antibodies and L1-specific cytotoxic T-lymphocytes after oral administration of crude extracts of L1-expressing insect cells. In conclusion, all three assembly forms of the L1 protein are immunogenic when administered orally.

Reducing the health burden of HPV infection through vaccination

Human papillomavirus (HPV), a sexually transmitted infection and the etiologic cause of genital warts and cervical cancer, is highly prevalent in sexually active men and women. Although cervical screening procedures have significantly reduced the disease burden associated with HPV infection, they are expensive and abnormal results cause significant emotional distress. Therefore, prevention may be an effective strategy for reducing the economic, psychosocial, and disease burden of HPV infection. Multivalent vaccines are now in clinical development. A bivalent vaccine that protects against HPV 16 and 18, and a quadrivalent vaccine which protects against HPV types 6, 11, 16, and 18, have been shown to significantly reduce the occurrence of incident and persistent HPV infections in phase 2 clinical trials; phase 3 trials are currently underway. HPV vaccines will be most effective when administered prior to initiation of sexual activity, and vaccination campaigns should aggressively target preadolescent and adolescent populations.